Regular and periodic filtration of cooking oil can extend the oils useful life by removing water and food particles. Portable cooking oil filters are known. For example, EP 241617 to FRYMASTER CORPORATION describes a portable unit where oil is removed from a cooker filtered in the unit and then returned to the cooker. Similar units are described in U.S. Pat. No. 5,870,945 to BIVENS; GB 2,146,547 to RENOVAT CLEANING AND FILTERING SERVICES(AUSTRALIA) PTY LTD; GB 1,426,323 to WHITESIDE; EP 381355 to FILTERCORP INC; U.S. Pat. No. 5,597,601 to GRIFFIN; U.S. Pat. No. 5,340,471 to WILSON ET AL; US 2004/0058043 to MORE.
All of these units filter the oil but have variations as to the unit structure and processing of the oil through the unit. As a result of these structural and processing variations each unit has its own advantages and disadvantages and in particular lack simplicity. U.S. Pat. No. 5,870,945 and US 2004/0058043 use of an inlet wand but this is not part of a circulation stream through the filters. U.S. Pat. No. 5,340,471 uses a single wand but has no circulation capability using a reversible pump to return filtered oil. U.S. Pat. No. 5,597,601 uses a single wand but unlike other units lacks an onboard storage tank.
EP 381355 uses a single wand. GB 1,426,323 does not have an onboard storage tank and uses a single process line and has no circulation capability. U.S. Pat. No. 5,870,945 does not use an inlet wand and has an open topped tank. Circulation within the unit is via an outlet wand. The inlet wand is effectively an extension of the open topped tank. The tank is filled under gravity. The filter is contained inside the tank. GB 146 547 uses a single wand, does not have a circulation capability using reversible pump. EP 241617 uses a single wand while US 2004/0058043 has circulation via a valve system.